#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
struct A
{
	char a;
	int b;
};

#define offset(type,member) (&(((type*)0)->member))
int main()
{
	struct A* p = 0;
	//p->a;
	printf("%d\n", offset(struct A, b));
	printf("%d", sizeof(*((struct A*)0)));
	return 0;
}